/Engine/Source/Runtime/Engine/Classes/Kismet/KismetMathLibrary.h
Converts a RGB linear color to HSV (where H is in R (0..360), S is in G (0..1), and V is in B (0..1))
static void RGBToHSV_Vector ( [FLinearColor](API\Runtime\Core\Math\FLinearColor) RGB, [FLinearColor](API\Runtime\Core\Math\FLinearColor) & HSV )